A variety of prior art methods and systems are known for sampling the liquids and gasses generated during drilling operations and, especially, exploratory drilling. Furthermore some of these prior art systems employ vacuum assist. For example, U.S. Pat. No. 2,112,845 describes an aspirator for drawing gas from the bottom of a borehole. U.S. Pat. No. 2,374,227 teaches positioning a vacuum bottle which is opened to collect a sample. U.S. Pat. No. 3,685,645 describes a fluid-circulating process for sampling the fluid in the soil around a borehole in which plugs or packets are promptly inserted in freshly drilled boreholes and are arranged to permit a stock fluid of known concentration to be circulated into repetitive contact with the soil exposed by the borehole. The concentration of the soil gas components are then measured when they have attained a substantially equilibrium concentration in the fluid being recirculated. However, such prior art methods have suffered from inconsistency. Consistency is particularly difficult to attain because relatively low concentrations of significant fluids such as hydrocarbons are present in the air or water present in the soil around the borehole.
U.S. Pat. No. 3,857,289 proposes a method of soil sampling using the auger, itself. The method includes using a telescoping auger that has extendable, internal conduits. The auger has teeth and flightlings arranged to form a substantially cylindrical borehole without causing any significant regrinding of soil particles. Auger rotation is stopped, and soil laden flightlings are moved away from the bottom of the borehole. The auger includes a pair of conduits which are then opened into fluid communication with the space between the auger flightlings and the borehole bottom. Fluid containing relatively small and known amounts of the component to be measured is circulated through the conduits and the exposed portions of the borehole and a measuring device in order to entrain and measure at least one component of the fluid in the soil around the borehole. While the method disclosed in the '289 patent is said to permit fluid sampling without allowing atmospheric contamination, it does require a determination of auger rotation and the moving away of the flightlings from the bottom of the borehole so as to open the conduits. Obviously having to stop the auger rotation each time a sampling is made is highly undesirable to efficient operation. Just as obviously, then having to remove the auger from the borehole after each sampling is also highly undesirable.
It would be desirable to provide a device for and a method of in-ground vapor monitoring which can be performed during operation of the auger and on a continuous basis, if desired.
It would be further desirable to provide such a device and method which is achieved by the use of modular drilling components which may be retrofitted onto existing drilling rigs.